I am in the process of moving my computers to Ubuntu. Things are going pretty well on my first installation, but during the process I began to have serious internet connection problems. I know this problem has nothing to do with the O/S, because I have the problem with any PC on my network, regardless of which version of Linux I am using. Because all my efforts going forward will be on Ubuntu, I figured this was the best place to come.
I have a home network using DSL that has been working reliably for roughly 9 months. It started giving me connection problems 2 days ago, which was March 1st when I originally wrote this. Since first entering this, I obtained a new switch and that has improved the situation considerably.
The current status, as or March 5th, is that with the new switch in place, the original configurations mentioned, now labeled 'Route 1' and 'Route 2' are now both working.
I have considered closing this issue, but I am going to add 'Route 3', which is part of my network, but totally working. 'Route 3', daisy chaining switches off the main switch, has been part of the network since I set it up about 9 months ago. Physically, it is much more convenient than the alternative, the alternative being to run maybe an extra 6, 50-to-100 foot ethernet cables through my house. If the consensus is that I do that, I will close this issue.
The test I am using is: ping www.google.com
Below is 'Route 1' a configuration that works, where 'EL' is an ethernet link and 'SW' is a switch. With this configuration, I get normal results from the ping, with 64 byte messages being received back from www.google.com.
modem --> wired link --> router --> EL --> Ubuntu PC
Below is 'Route 2' which has an ethernet switch added. This configuration, shown below, now also passes.
modem --> wired link --> router --> EL --> SW --> EL --> Ubuntu PC
The final configuration, 'Route 3' is shown below.
modem --> wired link --> router --> EL --> SW1 --> EL --> SW2 --> EL --> Ubuntu PC
I currently have 4 ethernet links coming out of switch 'SW1'. One of those links fits the 'Route 2' diagram and works. The other 3 links are 'Route 3' links to the computers. Two of these links pass. The third link fails, with a slightly different error message, presumably because the are running different Linux distributions.
When I ping from the Ubuntu host, using the 'Route 3' configuration, the error message is:
ping: www.google.com: Name or service not known
When I ping from the non-Ubuntu host, again using the 'Route 3' configuration, the error message is:
ping: www.google.com: Temporary failure in name resolution
Both indicating that the name was being translated to an IP address.
From either computer I can ping the router, but not www.google.com.
When I run lshw using 'Route 3', I get the following:
lshw -C network *-network description: Ethernet interface product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:01:00.0 logical name: enp1s0 version: 06 serial: 00:30:67:cd:16:04 size: 1Gbit/s capacity: 1Gbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=full firmware=rtl8168e-3_0.0.4 03/27/12 ip=192.168.0.251 latency=0 link=yes multicast=yes port=MII speed=1Gbit/s resources: irq:26 ioport:e000(size=256) memory:d0004000-d0004fff memory:d0000000-d0003fff
When I run tracepath using 'Route 2', I get:
tracepath www.google.com 1?: [LOCALHOST] pmtu 1500 1: router 0.613ms 1: router 0.566ms 2: router 0.536ms pmtu 1492 2: 10.7.0.69 18.574ms 3: 172.16.10.57 25.352ms 4: no reply 5: no reply
and 'no reply' repeats until I break out of tracepath.
If I run tracepath using 'Route 3', then tracepath hangs with no output.